(1) Field of the Invention
The present invention relates to particles that comprise a specific inorganic carrier material in a minimum amount of 30 wt. %, perfume and nonionic surfactant(s) in amounts of at least 0.1 wt. %, to a process for manufacturing such particles, to a detergent composition comprising such particles, and to a method for washing textiles with the help of this detergent composition.
In the washing, treatment and after treatment of laundry, it is now common practice to add small amounts of perfume to the detergents and after treatment compositions in order to confer a pleasant fragrance to the wash- or rinse liquor itself and also to the laundry treated with the wash- or rinse liquor. In addition, besides color and appearance, the perfuming of detergents and after treatment compositions is an important aspect of the aesthetic product impression and an important factor in the consumer deciding for or against a certain product. For perfuming, the perfume may either be directly incorporated into the composition or may be added to the wash or rinse liquor in an additional step. The first method establishes a certain product characteristic whereas, in the second method, the consumer can individually choose his or her fragrance from the various fragrance variants on offer—as is the case for the choice of an eau-de-toilette or an aftershave lotion.
(2) Description of Related Art, Including Information Disclosed Under 37 C.F.R. §§ 1.97 and 1.98
Accordingly, scented molded articles and processes for perfuming wash- and rinse liquors are extensively described in the prior art. Thus, DE 41 33 862 (Henkel) discloses tablets containing carrier materials, fragrances and optionally other typical detergent and cleansing agent ingredients, wherein sorbitol is the carrier material and in addition 20 to 70% by weight of an effervescent system of carbonate and acid are employed. These tablets, which may be added, for example, in the after-rinse cycle or fabric softening cycle of a household washing machine, comprise about 3 to 15% by weight and preferably 5 to 10% by weight of fragrance. As a result of their high disintegrator content, the tablets are sensitive to atmospheric moisture and have to be stored in a suitably protected manner.
In DE 39 11 363 (Baron Freytag von Loringhoven) a process is described for the production of a fragrance-enriched wash- or rinse liquor and a fragrance additive composition suitable for this purpose. The additive compositions, present in the form of capsules or tablets, comprise the fragrance together with an emulsifier in liquid form (capsules) or fixed to fillers and carrier materials (tablets), sodium aluminum silicates and cyclodextrins being cited as the carrier materials. The fragrance content of the capsules or tablets is at least 1 g for a capsule or tablet volume of more than 1 cm3. Tablets or capsules containing more than 2.5 g of fragrance for a volume of at least 5 cm3 are preferred. For storage, tablets or capsules of the type in question have to be provided with a gas- and water-tight outer layer to protect the ingredients. This publication does not provide any further details of the production or the physical properties of suitable tablets.
In International Patent Application WO 94/25563 (Henkel-Ecolab) a process is described for the production of molded bodies of detergents and active cleansers by means of the microwave technique that does not involve any high-pressure tableting. The molded bodies produced by this process are characterized by an extremely high rate of dissolution or disintegration coupled with fracture resistance without the need for a disintegrator. At the same time, they are storage stable and can be stored without any additional precautions. Molded bodies with a perfume oil content of 1 to 3% by weight that is typical for detergents and cleansing agents, can also be produced by this process. In general, perfume oils are readily volatile and, accordingly, could even evaporate on exposure to microwave radiation. If, therefore, relatively high levels of readily volatile liquid substances are to be used, then a two-component system consisting of a component produced by the microwave technique and a component comprising the sensitive liquid substances is described.
Particulate additives for perfuming wash liquors and for use in detergents and cleansing agents, together with processes for their production, are described in International Patent Applications WO 97/29176 and WO 97/29177 (Procter & Gamble). According to the teaching of these documents, perfume is added to porous carrier materials (for example, a mixture of sucrose and zeolite X), a coating material (carbohydrates) is then applied and the required particle size distribution is established.
German patent application DE 197 35 783 A1 (Henkel) describes highly concentrated scented molded bodies comprising carrier material(s), 20 to 50% by weight of fragrance(s) and optionally other auxiliaries and additives typical of detergents and cleansing agents, wherein at least 50% by weight of the molded bodies—after subtracting the quantity of fragrance—consists of fatty acids and fatty acid salts. These scented molded bodies are suitable both for perfuming detergents and cleansing agents and for perfuming laundry in a washing machine.
A process for applying fragrances to laundry in a washing machine is described in DE 195 30 999 (Henkel). In this process, a fragrance-containing molded body produced by exposure to microwave radiation is used in the final rinse cycle of a washing machine. According to the teaching of this document, the preferably spherically shaped bodies with diameters above 3 mm and bulk densities of up to 1,100 g/l are produced by introducing a mixture of predominantly water-soluble carrier materials, hydrated substances, optionally surfactants and perfume into suitable molds and sintering the mixture by exposure to microwave radiation. The fragrance contents of the molded bodies are between 8 and 40% by weight and the carrier materials used include starches, silicas, silicates and disilicates, phosphates, zeolites, alkaline salts of polycarboxylic acids, oxidation products of polyglucosans and polyaspartic acids. A crucial pre-condition of the process described in this document for producing shaped bodies is that to form molded bodies, at least partly bound water should be present in the mixture to be sintered by microwave radiation i.e. the starting materials should be at least partly present in hydrated form.
The proposed solutions cited in the prior art require either additional barrier layers or coating layers to fix the perfume to the carrier, or are not equally suitable for perfuming detergents and cleansing agents, and for direct use as the sole fragrance, for example, in the final rinse cycle of a washing machine.